Using GPG-agent, the ssh-agent does not show the keys using "ssh-add -l"

Question

I've been trying to get a yubikey to work as an authentication method for remote connections via ssh using this guide. I got the gpg2 set up nicely, and I can see that i've loaded the key onto the card by

gpg2 --card-status

I've exported it using

gpg2 --export-ssh-key > [keyname].txt

and can see the resulting key nicely. I've got my gpg-agent.conf set up as follows :

#config pinentry-program
pinentry-program /usr/bin/pinentry

#ssh support
enable-ssh-support

#write env inf to .gpg-agent-info
write-env-file
use-standard-socket

#default cache timeout
default-cache-ttl 600
max-cache-ttl 7200

and have modified my .bashrc as given in the guide. Any ideas where I might look for a solution?

Answer 1

Okay, so I got it working after tinkering for a while and reading the gpg-agent manpage here. I needed to add

unset SSH_AGENT_PID
     if [ "${gnupg_SSH_AUTH_SOCK_by:-0}" -ne $$ ]; then
       export SSH_AUTH_SOCK="${HOME}/.gnupg/S.gpg-agent.ssh"
     fi

to my .bashrc for the SSH_AUTH_SOCK to point to the correct place instead of the ssh-agent.